(1) Field of the Invention
The present invention is directed to a medical device, and, more particularly, to a trocar assembly which can be inserted a short distance into the abdominal cavity and expanded to prevent the device from sliding in and out of a surgical incision.
(2) Brief Description of the Prior Art
Endoscopic surgical procedures gain access to the inside of an anatomical cavity by first using an implement, such as a trocar spike, cannula or a needle having a sharpened point to pierce or puncture the bodily tissues, muscles, membranes, or the like, which may form a portion of or surround, the cavity wall.
Similarly, in many endoscopic procedures, a small incision may be made in the skin of a patient along the abdomen, for example, and the sharp point of a larger penetrating implement, such as a trocar spike of suitable length and diameter, may be inserted into the incision, and pushed until the point punctures the cavity wall. Thereafter, a sleeve is slid over the exterior surface of the implement into the puncture wound to serve as a lining for preserving the shape of the passageway created by the implement and for insertion of an endoscope, laparoscope, or the like, to view and operate upon organ within the cavity.
In many such applications, a trocar is used which incorporates a sleeve which may have a tendency to slide in and out of the incision in the abdominal wall, particularly when the surgeon is trying to move the laparoscopic instrument through the interior of the trocar sleeve into or out of the abdominal cavity.
One solution to such prior art deficiencies is discussed in U.S. patent application Ser. No. 440,199, filed Nov. 22, 1989, entitled "Looking Trocar Sleeve", and assigned to the same assignee as the present invention. In such application, concentric sleeves are disclosed, with the outer of the sleeves being manipulatable between contracted and expanded outer diameters to form a mushroom-like configuration at the distal end of the device which has been inserted into the abdominal cavity, such that resistance to withdrawal movements is effected when the surface of the mushroom contacts an abdominal wall. The activation of the mushroom is effected by a comparatively complex rotational or other mechanism, as disclosed. Moreover, the outer member which is "mushroomed" is not the member which, itself, is directly activated.
The present invention addresses the deficiencies of the prior art, as set forth above.